class_docstr: Implements soft-termination (zero discount) on life loss.
code: def reset(self) -> dm_env.TimeStep:
      timestep = self._environment.reset()
      self._reset_next_step = False
      self._last_num_lives = timestep.observation[LIVES_INDEX]
      return timestep
  
imports: import abc
  from typing import Tuple, List, Optional, Sequence, Union
  from acme.wrappers import base
  from acme.wrappers import frame_stacking
  import dm_env
  from dm_env import specs
  import numpy
  from PIL import Image
label_desc: Use image node_id 2 for calling the _ZeroDiscountOnLifeLoss obj's underlying member method code with example usage: obj.reset() and returns: timestep